The Neglected Sun: How the IPCC managed to forget natural variability in their climate models

By Sebastian Lüning

For many years it was suggested that the pre-industrial temperature and extreme weather history before 1850 might have been monotonous and stable. Meanwhile, a large number of palaeoclimatological and geological studies have comprehensively demonstrated that this model can no longer be upheld. Over the past 10,000 years, temperatures and extreme weather have been continously fluctuating, following milennial, centennial and multi-decadal natural cycles. While some of these changes are driven by auto-cyclical processes originating in the climate system itself, other fluctuations are clearly linked to external drivers, namely solar activity changes. The presentation reviews key case studies that point to a much strong involvement of solar-driven climate change than previously assumed by the Intergovernmental Panel on Climate Change (IPCC). Is it pure coincidence that the 20th century warming occurred at a time when the solar magnetic field more than doubled and during the second half of this period reached an activity level that has rarely been achieved over the last 10,000 years? It is further demonstrated that prominent Atlantic and Pacific ocean cycles (AMO, PDO) with periods of about 60 years modulate the longer term temperature development and between 1977-1998 have led to an amplified temperature increase which the IPCC has mistaken as a long-term warming rate.